Track-circuit system



1931- 'A. G. WILLIAMSON TRACK CIRCUIT SYSTEM Original Filed April 5. 1922 351 8 10 abhor/nut Patented Feb. 17, 1931 UNITE D STA .lLRlBA e. Wi LLIAMSON, or: CABNEGtIl, A ASSIGNOR; Y

MENTS, T 'rnE NION swrrcn a SIG1\ T AL CQM1?ANY, OF

VANIA, .A CORPORATION I F PENNSYLVALTIA PME B ReQK-Q E I s t 3M priig inal applicat iqn filed April 5, 15122, Serial 131 549352 rat ntno'. 1,683,222, datea September 4, eas.

This invention relates to track circuit sys tems particularly for use in connection train control systems of the type disclosed'in applications Serial No. 555304;, filedlepril 8,1 nd is a d vis n o epp set e b rial No. 549,662, filed April5,'1- 9225 which matu d t Patent N l 2 2 k1ate 1 epber ,1928 I I a i The main object and featureof the nvention is to prQVide a simple form of track it eans whereby an in fi jile' atsd 9 l we n a plural ty 9f tra ir i may be effected. l V

Mor particu a y th s ev nti n re at s to a track cireuitjsystem for use with tra n control systems of the type comprising train ca-rried means controlled by energy received from circuits including the traffictrack.

In the accompanying drawing apreferred form of the invention is disclosed, the drawing showing a diagrammatic View of the track circuit system. j

7 Referring to the drawing, land 2 represent the rails of a traffic track divided into blocks W, X, Y and Z in a manner well imderstoodhy mea s of nsulat on 3.- s and 5 indica W n f dby a si le frequee y nera r ess eiat d w th each 1991; s a m -t an rmer i dicated by T1 T 0 a d The secondary 6 of each of these transformers is connected by means of conductors 7 and 9 with a primary 8 of a track transformer associated with each block and indicated variously as Nw, N00 and N1]. The secondary 7 13 of each of therespective track transformersis connected by suitable leads With rails 1' and 2th'e'rebysupplying eurrent to both of saidrafls bi a g v f lb k nt rm ed e- "seen s nes the mai ns ere andprimry set the ma; trans, ,i'rc'uit breake i t e form of a pqle ha ger d8 se e MP; ean 21 o 't'he respe uvsuoeksw, Xend'Yl I Each hlQsk i a so p i e Wlth track esignated aslm, y These p y are of the two element polarized type that 1s well known in the art. One element is connected by suitable leads to the t-raflic rails of a block. The second element Q of each relay is connected to the wires 7 and former.

the circuit iustitracfld wi l e Sand therefore fed by the secondary 6 of the main transformerT. V o I Thus these polarized trackrelays are influenced both by the track circuitcurrent and by currentfrom transformer T. 1

, It is well; known that where the-instanta neous polarity ofboth elements is'such that the currents in both elements are in phase that the armature will swing to oneposition,

let us say, to right hand position. If the connection of one element should be reversed so that the instantaneous polarity of the currents in the two elementsare out of phase then armature 100 will swing to the left hand position. If current is absent in the track ele-- ment then armature 100 Will-hang in a center position. Reversal'of the instantaneous polarity of the current in the track railsis accomplished by the pole changer reversing the connections to the primary of the track'trans- The pole changer is actuated b-y-a repeater relay 150, which is connected by wire 151to the wire 9 and to the Wire 7 through either the left hand contact 152 or right hand contact 153 and the armature 100 of thetrack relay with'which it is associated. Thus the repeater relay for a block is energized when the track relay is energized'with either normal or reverse polarity (if current and is A deenergized energized. V

In addition to the ahoye descifihed track Wheni h W91? e ay i decircuit which includes thetraiiictrack; each blQCklS provided with a seeond track circuit which also includes traflic track.

Geesected 1 9 see s91? f as ele eedw 6 leads conductorlfil impedance 102 wire 103 and to ground Againifroin the primary 8 i the ack transf mer N l a s e shun connection 1.0.5 to the wireilfl leadingtothe rail 1 of the trai'fic track Inasmu'c-l-riasthe fails 9f the track.

are to a cert ain eiitent insulated fro tial on the traffic trafik ha allo s ground potential. Thatis to say the insulation, is of course not perfect and iwhile there eXiSiS leakage of current it is not egm'essi ye Sflthat voltage above ground potential is maintained on the trafiic track of the block.

While the current flowing in the first de scribed track circuit is preferably used to infiuence a coordinating train carried circuit as well as to control wayside circuits, the second described track circuit is to be used to influence a coordinating train carried circuit.

When a train K occupies the block Z as shown in the drawing, the track relay L2 is deenergized and its armature 100 drops to the center position thereby rupturing the circuit through the repeater relay 150.2. Relay 150.2 dropping the pole changer Py causes current of one polarity to be supplied to the track transformer Ny. Also dropping of Pg cuts out the energizing of the second track circuit for the block Y, inasmuch as the lead to the ground and the shunt lead around the track transformer N2 are both connected to the same terminal of the secondary of the main transformer Ty. Thus the traiiic track of block Y to the rear of the occupied block Z is supplied with but one current.

The reverse current flowing in the block Y energizes the track relay Ly so that its armature 100 swings to the left hand position to close the circuit to the repeater relay 150 Relay 1501 being now energized lifts the pole changer P00 whereby the first track circuit of the block X is supplied with current of normal polarity. Furthermore, the lifting of pole changer Pm causes the second track circuit for the block X to be energized by the following circuit: secondary 6 of The, wire 9, lower arm of pole changer P00, wire 7, wire 105, wire 14, impedance and to rail 1, and the opposite terminal of secondary 6, wire 7, wire 101, impedance 102, wire 103 and ground.

Thus the trafiic track of the block X, the second block to the rear of th occupied block Z, is supplied with two currents.

I claim:

1. A track circuit system including: a traffic track divided into blocks, two normally closed track circuits for each block, each of which circuits includes the tratlic track, a polarized relay for each block energized by one of said track circuits, a repeater relay for each block energized when the said po larized relay of the same blockis energized with either normal or reverse polarity of current, and deenergized when said polarized rclay is deenergized, and a circuit breaker controlled by said repeater relay to reverse the polarity of the current supplied to the track circuit that energizes the polarized relay of another block and to permit and prevent the energization of the second track circuit of said other block.

2. A track circuit system including a traffic track arranged in blocks, two normally closed track circuits for each block, each of one of said track circuits, and a second relay for each block controlled by the polarized relay of that block, said second relay arranged, when the polarized relay by which it is controlled is energized by either normal or reverse polarity of current, to permit current of normal polarity to be supplied to the track circuit that energizes the polarized relay for the block in the rear, and also to permit the energization of the second track circuit for the said block in the rear, and said second relay arranged to permit current of reverse polarity to be supplied to the track circuit that energizes thepolarized relay for the block in the rear and to prevent energization of said second track circuit for the block in the rear when the polarized relay by which said second relay is controlled is deenergized.

3. A' track circuit system including a traffic track arranged in blocks, two normally closed track circuits for each block, each of which circuits includes the trafiic track, a polarized relay for each block controlled by one of said track circuits, a repeater relay associated with each polarized relay and conb trolled thereby, and armatures actuated by said repeater relay arranged to control the polarity of the current being supplied to the track circuit that controls the polarized relay of another block and to permit and pre vent the supplying of current to the other track circuit of said other block.

at. A track circuit system including: traf fic track arranged in blocks, two normally closed circuit means for supplying current to the traffic track of each block, a polarized relay for each block energized by current supplied to the traific track by one of said circuit means, and a second. relay for each block controlled by the polarized relay of that block. said second relay arranged, when the polarized relay that controls said second relay is energized by either normal or reverse polarity of current, to permit current of normal polarity to be supplied to the traflic track for the block in the rear by the circuit means that energizes the polarized relay of said block in the rear, and also to permit current to be supplied to the traffic track for said block in the rear by the second circuit means of said block in the rear, and said second relay arranged, when the polarized relay by which said second relay is controlled is deenergized, to permit current of reverse polarity to be supplied to the traiiic track for the block in the rear by the circuit means that energizes the polarized relay, and to prevent current to be supplied to the traffic track for the block in the rear by the sec ond circuit means.

Signed at Washington, in the District of Columbia, this 16th day of August, 1928.

ABBA G. WILLIAMSON.

which circuits includes the traffic track, a

polarized relay for each block energized by llO 

